Microfluidic detection systems and microfluidic cartridges of such systems are well known in the art. Such microfluidic detection system usually comprises a detector assembly and at least one microfluidic cartridge, where the microfluidic cartridge is shaped to hold a sample e.g. a liquid sample in a flow channel of the microfluidic cartridge. The microfluidic cartridge can be inserted into a slot of the detector assembly for optical analyses. Such microfluidic detection systems are usually used for performing analysis of liquids very fast and at relatively low cost. Often such microfluidic detection systems are used for high through put analysis. Due to development of standard analyses which can be performed at the doctor or even at a home of a patient, it is required that the general cost for the microfluidic detection system is relatively low.
Many of the standard analysis require that the sample should be subjected to several tests using optical light sources having different wavelengths.
U.S. Pat. No. 3,910,701 discloses an apparatus for measuring light reflectance, absorption and/or transmission having a plurality of light emitting diodes (LEDs) arranged to direct light emissions toward a test piece, with the various diodes being selected to emit light of different wavelengths and at least one light-responsive sensor disposed to receive light reflected and/or transmitted by the test piece and originating with each of the light-emitting diodes. Electrical drive circuit means are provided for alternately or sequentially energizing the plurality of LEDs of different wavelengths, such that the reflected or transmitted light received by the sensor is a function of the various wavelengths of the respective LEDs. The plurality of LED sources and the light responsive sensor are mounted within a self-contained module, of size and shape similar to a camera lens, and the module is detachably connected to a portable housing for the instrument. In this manner, a number of different source modules may be provided for each detection site simply by moving the module.
U.S. Pat. No. 7,791,728 discloses a microfluidic analysis system for optically analyzing a substance that includes a light source having a plurality of selectable single-wavelength light sources, a substance presentation member optically coupled to the light source, and an optical detection system associated with the substance presentation member. The light source and wavelength selection system include a light generating carousel having a plurality of single-wavelength light sources coupled thereto. The carousel can be rotated for position of the desired single-wavelength light source for a test. The microfluidic analysis system is suitable for completing an optical analysis on a millimeter or microliter scale volume of fluid due to the use of the multi-wavelength selector structure having multiple single-wavelength light sources such as light emitting diodes (LEDs) or lasers.